The present invention relates to a service providing system that distributes data to user terminals (hereinafter referred to as a terminal) over the network, and more particularly to a service providing system that can provide a service that is best suited for a request from each terminal, by referring to a device identification code (hereinafter referred to as a device ID) uniquely assigned to each terminal.
With the recent rapid development of the Internet, various problems such as shortage of address space have occurred in the currently used Internet protocol version 4 (IPv4). To solve the problems, Internet Protocol version 6 (IPv6) (i.e., the next generation of the Internet protocol) is under development. The IPv6 is characterized by having an extremely large number of IP addresses. The 128-bit address space of the IPv6, where 3.4×1038 addresses are available, can solve the problem of the shortage of IP addresses which occurred in IPv4. This also permits each terminal to have its own device ID contained in an IP address.
A prior service providing system that distributes data, as a service, to each terminal will be described as follows. The conventional service providing system manipulates, as a distribution service, such data as a still picture, a moving picture, and audio. Each of these types of data needs to have its own data format available for use in computers. In this service providing system, in response to access requests from terminals, a server reports a list of distributable data formats to each of the terminals. The terminal reports back a data format available for use in itself to the server. This prompts the server to provide the services to the terminal.
However, the use of Personal Digital Assistants (PDAs) as a terminal often limits the number of data formats available for use in the terminal. Thus, the list of data formats provided by the server is often sure to include data formats the terminal cannot manipulate, thereby causing an unnecessary data exchange over the network. In addition, the terminals that can manipulate less data formats tend to have a less powerful Central Processing Unit (CPU). This burdens such terminals with an unnecessary task of selecting a compatible data format from the limited selection.
In addition, message exchanging with a server, together with such information as a data format or a parameter, with the terminal that can manipulate only a single data format, not only complicates the data communication, but also causes a delay to the distribution service. The delay is accelerated in proportion to the distance between the server and the terminal.
JP-A No. 283247/1998 discloses a method of providing a service meeting the request from each terminal. The method includes a step to allocate each terminal its own device ID information for its identification, a step for the terminal to transmit the device ID information to a server, and a step for the server to return a list of files available for downloading by the terminal. However, the method does not cover data accessing that needs to manipulate a number of data formats such as of a moving picture and a still picture. Thus, the data accessing needs to have those data formats adapted for each terminal.